Melanoma is an immunogenic tumor that can metastasize quickly to proximal and distal sites, thus complicating the application of therapeutic modalities. Numerous mouse model systems have been used to gain understanding of the immunobiology and metastatic potential of melanoma. Here, we report the optimization of a syngeneic mouse melanoma model protocol using the mouse B16-derived melanoma cell line B16F10 that ensures the production of tumors on mice pinnae that are similar in size between animals and that enlarge in a time-dependent manner. In this model, B16F10 cells are first allowed to develop tumors after injection in the interscapular area or flank of C57BL/6J mice. Subsequently, the tumors are harvested, cells dissociated and injected into mouse pinnae. Dose-dependent studies revealed that injection of 2 × 10 5 cells allowed for slow tumor enlargement, producing tumors averaging 100 mm 3 within 2 to 3 wk with a metastatic frequency of 100%. This experimental protocol will be useful in dissecting the immunobiology of melanoma tumor development and metastasis and the evaluation of immunotherapeutic antimelanoma therapies.

12034 Background: Breast cancer is the 2nd leading cause of cancer-related death in women with existing barriers in preventive services, access to treatment, and end-of-life care. There are unique sociopolitical challenges to rural healthcare with gaps in national health funding and hospice infrastructure. We investigated rural-urban disparities in age-adjusted mortality rates (AAMRs) and place of death in individuals dying from breast cancer. Methods: CDC WONDER database was utilized to analyze deaths from breast cancer from 2003 to 2019 using population classification per 2013 US Census: large metropolitan (≥1 million), small- or medium-sized metropolitan (50,000-999,999), and rural areas (< 50,000). We extracted AAMRs by geographic area, age, and race/ethnicity. We estimated annual percentage changes (APC) in AAMR using robust linear regression models of the log-scale AAMR, including population size as weights, and assessed differential changes over time by geographic area with interaction tests. We estimated the percent of all deaths occurring in medical, hospice, and nursing facilities, and home. Odds ratios (OR) for the association between each place of death and individual-level characteristics were calculated using logistic regression, adjusting for year of death. Differential changes in place of death over time by geographic region were assessed with interaction tests. Results: From 2003 to 2019, there were 676,532 breast cancer-related deaths (52.9% large metro, medium/small metro 30.3%, rural 16.8%). Total AAMR declined from 39.8 to 30.9 during this period with rural areas noting least improvement (APC -1.24, 95% CI [-1.39, -1.09], p < 0.001 for time trend) compared to large metropolitan (APC -1.74, 95% CI [-1.63, -1.46]). Non-Hispanic Black women had higher AAMRs among all racial/ethnic groups. Across all years, women in large metropolitan (OR 2.02, 95% CI [1.96, 2.07]) and medium/small metropolitan (OR 2.19, 95% CI [2.12, 2.25]) had higher odds of dying in a hospice facility compared to rural areas. Rural women died least often in a hospice facility (9.7% vs 14.5% large metropolitan vs 16.9% medium/small metropolitan in 2019), more often in a nursing facility (19.2% vs 12% large metropolitan vs 13.9% medium/small metropolitan) and slightly more often at home (44.6% vs 41.7% large metropolitan vs 43.4% medium/small metropolitan). Women in large metropolitan areas were most likely to die in a medical facility. Conclusions: Rural women with breast cancer experienced greater mortality and least annual improvement, with notable disparities in place of death. Our findings support interventions to improve access across cancer care continuum and congressional policy to urgently re-invest in cancer care access in rural areas.

e19055 Background: Socioeconomic disparities in healthcare have been well documented in America, with cancer being a critical area. One in four deaths are caused by cancer, and the effects on different communities are not equal. Clinical observations suggest that poorer socioeconomic circumstances lead to more frequent, later stage diagnoses and worse outcomes. The aim of this project was to quantify the sociodemographic and geographic contributions to disparities in advanced, metastatic breast cancer within the Augusta population and surrounding areas. Methods: Records of patients managed for breast cancer at the Georgia Cancer Center between Jan 2009- Jun 2019 were reviewed. 80 patients who presented with early stage breast cancer (clinical stage I) without positive lymph nodes were compared with 80 patients who presented with advanced, metastatic disease (clinical stage III-IV). Their race, breast cancer characteristics, insurance status, geographic proximity to a mammography site or major healthcare facility, and time interval between diagnosis and treatment were compared. Results: Results show that 73.75% early stage patients had private insurance, while 41.25% late stage patients had private insurance (p value < 0.0001). The early stage patients were 4.0 times more likely to have private insurance than late stage patients. Results also show that 25.0% of late stage patients had annual mammography screenings, while 77.78% of early stage patients had regular screening for mammograms (p value < 0.0001). The late stage patients were 1/10 as likely to have regular screening for mammogram as early stage patients. 80.6% of patients that received regular mammograms had private insurance, while the remaining 19.4% of those patients had public insurance. No statistical difference was shown in late and early stage presentation based on HER2 and/or triple negative (ER-, PR-, HER2-) status. Conclusions: There is a significant outcome of advanced, metastatic breast cancer in patients that do not have private insurance and in those that do not receive regular mammograms. Our findings support the importance of investing resources into alleviating differences in various socioeconomic populations as they relate to the amount and quality of cancer healthcare available. While the incidence of mortality in breast cancer is decreasing nationwide, disparities in morbidity and mortality will most likely continue unless there is an aggressive effort towards addressing said differences.

134 Background: Socioeconomic disparities in healthcare have been well documented in America, with cancer being a critical area. One in four deaths are caused by cancer, and the effects on different communities are not equal. Clinical observations suggest that poorer socioeconomic circumstances lead to more frequent, later stage diagnoses and worse outcomes. The aim of this project was to quantify the sociodemographic and geographic contributions to disparities in advanced, metastatic breast cancer within the Augusta population and surrounding areas. Methods: Records of patients managed for breast cancer at the Georgia Cancer Center between Jan 2009- Jun 2019 were reviewed. 80 patients who presented with early stage breast cancer (clinical stage I) without positive lymph nodes were compared with 80 patients who presented with advanced, metastatic disease (clinical stage III-IV). Their race, breast cancer characteristics, insurance status, geographic proximity to a mammography site or major healthcare facility, and time interval between diagnosis and treatment were compared. Results: Results show that 73.75% early stage patients had private insurance, while 41.25% late stage patients had private insurance (p value < 0.0001). Results also show that 25.0% of late stage patients had annual mammography screenings, while 77.78% of early stage patients had regular screening for mammograms (p value < 0.0001). 80.6% of patients that received regular mammograms had private insurance, while the remaining 19.4% of those patients had public insurance. No statistical difference was shown in late and early stage presentation based on HER2 and/or triple negative (ER-, PR-, HER2-) status. Conclusions: There is a significant outcome of advanced, metastatic breast cancer in patients that do not have private insurance and in those that do not receive regular mammograms. Our findings support the importance of investing resources into alleviating differences in various socioeconomic populations as they relate to the amount and quality of cancer healthcare available. While the incidence of mortality in breast cancer is decreasing nationwide, disparities in morbidity and mortality will most likely continue unless there is an aggressive effort towards addressing said differences.